Need help with my first LR308 build

[hevyjunk01]

FaRKle! - I've tried to tighten the buffer tube more however, that's as far as it will thread without removing the buffer tube spacer plate. I'll look at it again and see if I'm missing something on it.

Survivalshop - I also looked at the coils and count around 26 I'm not sure if this is due to it being an extra power spring with a thicker diameter of wire allowing for less coils. I'm going to the store tomorrow to look at a normal 308 spring.

[hevyjunk01]

FaRKle! - I'll get you a better pic of the spacer plate.

[hevyjunk01]

Here is the buffer tube spacing

[FaRKle!]

FaRKle! - I've tried to tighten the buffer tube more however, that's as far as it will thread without removing the buffer tube spacer plate. I'll look at it again and see if I'm missing something on it.

Survivalshop - I also looked at the coils and count around 26 I'm not sure if this is due to it being an extra power spring with a thicker diameter of wire allowing for less coils. I'm going to the store tomorrow to look at a normal 308 spring.

Here is the buffer tube spacing

Bummer. Still, in the latest photo it seems like the set screws aren't aligning the tube straight (look at the larger gap at the bottom from the big screw compared to the top lol).

An LR-308 carbine action spring has 29 coils.

[98Z5V]

OP, your receiver extension is the right depth for the recoil system you have.  So is your buffer.  That last pic of your BCG, and it's distance to the bolt catch - that's where you want to be.  If that's 2 quarters, run it.  If it's 6 quarters - run it.  whatever that is, that's what you're stuck with.

 

What this comes down to is machining.  Not good, but workable.  Just have to live with it.

 

EDIT - this is the reason you're seeing the issues that you are.  No need to look any further, test any other components, etc.  This is the issue, and it happens more often than you think.

 

 

I'm running a local company's upper and lower receiver's manufactured after DPMS.

Edited April 2, 2015 by 98Z5V

[survivalshop]

 Wonder how a std Receiver extension ( Carbine )  & DPMS spring would work out . The Buffer is the correct 308 Carbine Buffer , its the Receiver Extension & spring that are not common parts & as 98 pointed out , a unknown Receiver set . I looked at the Photo of the spring on JP's web sight & it has 26 coils , as yours does ( ever notice how mesmerizing it is to count the coils  <laughs> )

 They also state it is used for the 9MM rifle also . If the photo is correct for the spring , I can't see any thing from JP's being wrong for a build , but a combo of miss matched components can cause all kinds of problems as we have seen in the past . No matter what way you look at it , the BCG is going to far into the Receiver Extension .To me at first look would be weak or wrong spring .

 

 I would be willing to try a Tubb's Flat wire spring , I have one if you want me to send it to you to try ? 

[washguy]

 Wonder how a std Receiver extension ( Carbine )  & DPMS spring would work out . The Buffer is the correct 308 Carbine Buffer , its the Receiver Extension & spring that are not common parts & as 98 pointed out , a unknown Receiver set . I looked at the Photo of the spring on JP's web sight & it has 26 coils , as yours does ( ever notice how mesmerizing it is to count the coils  <laughs> )

 They also state it is used for the 9MM rifle also . If the photo is correct for the spring , I can't see any thing from JP's being wrong for a build , but a combo of miss matched components can cause all kinds of problems as we have seen in the past . No matter what way you look at it , the BCG is going to far into the Receiver Extension .To me at first look would be weak or wrong spring .

 

 I would be willing to try a Tubb's Flat wire spring , I have one if you want me to send it to you to try ? 

I know how it would work out and so do you Survival....perrrrfect  ...its always the "trick stuff" that puts you in the "trick bag"

    <lmao>     Wash

[hevyjunk01]

I've tested a different buffer spring and it works. I think the JP spring I had was for a different setup of some sort of which I'm not sure. The space between the coils for the JP is around 1/2" with a total of around 26 coils. The new spring I tested has a space between the coils around 1/4" and a total of around 39 or so coils depending on how you count. My distance is correct and does not bottom out. I also have proper clearance for the bolt catch to engage. Thanks for all of your help and time on this.

[FaRKle!]

I've tested a different buffer spring and it works. I think the JP spring I had was for a different setup of some sort of which I'm not sure. The space between the coils for the JP is around 1/2" with a total of around 26 coils. The new spring I tested has a space between the coils around 1/4" and a total of around 39 or so coils depending on how you count. My distance is correct and does not bottom out. I also have proper clearance for the bolt catch to engage. Thanks for all of your help and time on this.

39 coils? What kind of spring did you get??? Even an AR-10 spring only has 35 (with ~5/16" spacing between coils). Are you sure the buffer is bottoming out in the receiver extension now?

Edited April 3, 2015 by FaRKle!

[98Z5V]

Are you sure the buffer is bottoming out in the receiver extension now?

 

Right - is it bottoming out like it's supposed to, or is coil bind stopping it now.  that would be my concern as well.  Coil bind will lead to a broken spring, in short order.

[survivalshop]

 STD AR 15/16 Buffer spring has 39 coils . Have you shot the rifle with this spring in there ? You should try a DPMS 308 Carbine Buffer spring , it has 29 coils & may be enough difference . As 98 said , the Spring is probably binding or collapsing  to full compression.

 

  As I asked before , I have a Tubb's Flat wire spring you can try out , to see how it works & is Made for the 308AR . It works in both Buffer systems .

Edited April 3, 2015 by survivalshop

[hevyjunk01]

I've bought a 308 spring. The other one I had was a doublestar spring. Local shop sold me the ar15 spring. I had cut it down to size to fit. I'm going to get an actual 308 spring. I don't want any issues with the weapon once my current issues are fixed.

[Dane Armory]

I know how it would work out and so do you Survival....perrrrfect ...its always the "trick stuff" that puts you in the "trick bag"

<lmao> Wash

Hmmmm ! Have you guys noticed a pattern. It appears a lot of problems occur when someone buys ONE JP part and not the whole upgrade kit, their gun doesn't work !

I came on this thread too late to comment on the buffer spring. Oh well.

Edited April 3, 2015 by Dane Armory

[hevyjunk01]

It would be nice to have something dedicated for new builders to reference without having to search the web or other material for guidance during the building process. I'm looking at this as great experience for my future builds and overall knowledge when something does not add up. It's good to know there are people out here who are willing and helpful with this process. Thanks to all who have Helped.

[survivalshop]

  We were all where you are at one point or another , its how we learn . 
  Before you purchase something or a combination of components , ask if it will work , some one has used it or has an opinion about it . It also keeps you away from " The Rule ".

Edited April 3, 2015 by survivalshop

[hevyjunk01]

Could I run a regular 308 buffer 2.5" with a Springco (Orange) buffer spring? A buddy of mine has one and is willing to let me test it to see if it will work. I'm looking to try it out next weekend.

[washguy]

Could I run a regular 308 buffer 2.5" with a Springco (Orange) buffer spring? A buddy of mine has one and is willing to let me test it to see if it will work. I'm looking to try it out next weekend.

Heavy   I run that combo on my new build...works like a sewing machine   

:) Wash

[hevyjunk01]

Thanks for the info. I'm gonna try that and see if it fixes my issues.